This invention relates to a means for sampling the exhaust air of an air filtration unit and more particularly to means for the exhaust air of an air filtration unit which is being used in an asbestos abatement action.
Airborne asbestos contamination in buildings is a significant environmental problem. Various diseases have been linked with industrial exposure to airborne asbestos, and the extensive use of asbestos products in buildings has raised concerns about exposure to asbestos in nonindustrial settings. Surveys conducted by the Environmental Protection Agency (EPA) estimate that asbestos-containing materials can be found in approximately 31,000 schools and 733,000 other public and commercial buildings in this country.
In an effort to avoid the hazards associated with exposure to airborne asbestos, abatement actions or procedures are being extensively conducted and the Environmental Protection Agency has published a booklet entitled "Guidance for Controlling Asbestos-Containing Materials in Buildings". During the abatement action, one or more air filtration units, usually several air filtration units, are positioned throughout the work site to filter the air in the work area.
During the abatement action, it is recommended that the exhaust air of the air filtration units be monitored. Inasmuch as the exhaust of the air filtration units are normally exhausted to the atmosphere, the monitoring or sampling of the exhaust air is quite difficult. For example, if the abatement action is being conducted on the 14th floor of a high-rise building, it is extremely difficult to sample the exhaust air as the air is discharged from the 14th floor.
When a plurality of air filtration units are being used within the enclosed work site, and the exhaust of the same are being exhausted to the atmosphere outwardly of the building, the contamination problem is encountered when a particular air filtration unit is taken out of service for maintenance. For example, if an air filtration unit is shut down, back pressure on the exhaust side thereof can cause asbestos fibers to be discharged from the contaminated side of the HEPA filter into the work site when the air filtration unit is shut down.
Further, when a plurality of air filtration units have been used during the abatement action, a large number of the air filtration units must be shut down just prior to the final air sampling within the work site. When the air filtration unit is shut down, back pressure on the exhaust side of the air filtration unit can also cause the discharge of asbestos fibers into the work site, as previously described.
Therefore, it is a principal object of the invention to provide a means for sampling the exhaust air of an air filtration unit.
A further object of the invention is to provide a means for sampling the exhaust air of an air filtration unit and more particularly a means for sampling the exhaust air of an air filtration unit which is being used in an asbestos abatement action
Yet another object of the invention is to provide a means for sampling the exhaust air of an air filtration unit to permit the convenient sampling of the same.
Still another object of the invention is to provide a means whereby the exhaust of air filtration units may be selectively closed by means of dampers to prevent back pressure being subjected to the air filtration unit which could dislodge fibers from the HEPA filter and re-contaminate the work site.
Still another object of the invention is to provide a means for sampling the exhaust air of an air filtration unit including means for changing the air sampler cassettes without contaminating them or the exhaust air.
These and other objects will be apparent to those skilled in the art.